The Obama administration says flying the flag could give Haiti the wrong idea.
"We are not here as an occupation force, but as an international partner committed to supporting the government of Haiti on the road to recovery," the U.S. government's Haiti Joint Information Center said in response to a query about the flag.

The missing American colors at Port-au-Prince airport were no problem to Don Hollenbaugh, a former Army Delta Force operator who received the Distinguished Service Cross for actions in Fallujah, Iraq, in 2004.

"Everybody in the world knows the U.S. is there," Hollenbaugh said. "So by not flying the flag, we're not changing anyone's mind about anything."

During the Gulf War in 1991, U.S. forces took control of the main airport in Kuwait and briefly flew the American flag over their installation, Davis said, but higher-ups ordered it taken down to avoid an impression that U.S. forces were conquerors.

I believe that is the Billy Dee Williams signature call for a 40oz Colt 45 Malt Liquor treat.

Flying the flag should be the choice of the commander on the ground. I don't know that many soldiers really care. We should not be there to begin with. At least in Iraq we were eliminating a threat. In Haiti we are standing-up dominos to be knocked down by voodoo and the next hurricane or earthquake. Until the Haitians make the choice to build a solid infrastructure they are a doomed society.